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Tourette's Syndrome

A neurological disorder that affects men four times as often as it does women, Tourette's syndrome causes patients to have uncontrollable, involuntary tics and movements. These can sometimes manifest as uncontrolled shouts or vocalization.

Definition

Tourette's syndrome (TS) is an inherited, neurological disorder characterized by multiple involuntary movements and uncontrollable vocalizations called tics that come and go over years. In a few cases, such tics can include inappropriate words and phrases.

The symptoms of TS generally appear before the individual is 18 years old. TS can affect people of all ethnic groups; males are affected 3 to 4 times more often than females. It is estimated that 100,000 Americans have full-blown TS, and that perhaps as many as 1 in 100 show a partial expression of the disorder.

Not all people with TS have disorders other than tics. However, many people experience additional problems such as obsessive compulsive behavior, characterized by an intense need to act repeatedly, such as hand washing or checking that a door is locked; attention deficit-hyperactivity disorder, characterized by difficulty concentrating and staying on task; learning disabilities, which include reading, writing and arithmetic difficulties; or sleep disorders, which include frequent awakenings or talking in one's sleep.

The wide range of behavioral symptoms that can accompany tics may, in fact, be more disabling than the tics themselves. Patients, families and physicians need to determine which set of symptoms is most disabling so that appropriate medications and therapies can be used.

Generally, TS is diagnosed by obtaining a description of the tics and evaluating family history. For a diagnosis of TS to be made, both motor and phonic tics must be present for at least 1 year. Neuroimaging studies, such as magnetic resonance imaging (MRI), computerized tomography (CT), and electroencephalogram (EEG) scans, or certain blood tests may be used to rule out other conditions that might be confused with TS. However, TS is a clinical diagnosis. There are no blood tests or other laboratory tests that definitively diagnose the disorder.

Studies show that correct diagnosis of TS is frequently delayed after the start of symptoms because many physicians may not be familiar with the disorder. The behavioral symptoms and tics are easily misinterpreted, often causing children with TS to be misunderstood at school, at home, and even in the doctor's office. Parents, relatives, and peers who are unfamiliar with the disorder may incorrectly attribute the tics and other symptoms to psychological problems, thereby increasing the social isolation of those with the disorder. And because tics can wax and wane in severity and can also be suppressed, they are often absent during doctor visits, which further complicates making a diagnosis.

In many cases, parents, relatives, friends or even the patients themselves become aware of the disorder based on information they have heard or read in the popular media.

Symptoms

There are two categories of tics: simple and complex. Simple tics are sudden, brief movements that involve a limited number of muscle groups. They occur in a single or isolated fashion and are often repetitive. Some of the more common examples of simple tics include eye blinking, shoulder shrugging, facial grimacing, head jerking, yelping, and sniffing. Complex tics are distinct, coordinated patterns of successive movements involving several muscle groups. Complex tics might include jumping, smelling objects, touching the nose, touching other people, coprolalia, echolalia, or self-harming behaviors.

People with TS can sometimes suppress their tics for a short time, but the effort is similar to that of holding back a sneeze. Eventually tension mounts to the point where the tic escapes. Tics worsen in stressful situations; however, they improve when the person is relaxed or absorbed in an activity. In most cases, tics decrease markedly during sleep.

After delaying tics at school or work, people with TS often seek a secluded spot to release them.

Causes

Although the cause of TS is unknown, current research points to abnormalities in certain brain regions (including the basal ganglia, frontal lobes, and cortex), the circuits that interconnect these regions, and the neurotransmitters (dopamine, serotonin, and norepinephrine) responsible for communication among nerve cells. Given the complex presentation of TS, the cause of the disorder is likely to be equally complex.

Evidence from genetic studies suggests that TS is inherited in a dominant mode and the gene(s) involved can cause a variable range of symptoms in different family members. Although early family studies suggested an autosomal dominant mode of inheritance (one in which only one copy of the defective gene, inherited from one parent, is necessary to produce the disorder), more recent studies suggest that the pattern of inheritance is much more complex.

Although there may be a few genes with substantial effects, it is also possible that many genes with smaller effects and environmental factors may play a role in the development of TS. Genetic studies also suggest that some forms of ADHD and OCD are genetically related to TS, but there is less evidence for a genetic relationship between TS and other neurobehavioral problems that commonly co-occur with TS. It is important for families to understand that genetic predisposition may not necessarily result in full-blown TS; instead, it may express itself as a milder tic disorder or as obsessive-compulsive behaviors. It is also possible that the gene-carrying offspring will not develop any TS symptoms.

The sex of the person also plays an important role in TS gene expression. At-risk males are more likely to have tics and at-risk females are more likely to have obsessive-compulsive symptoms. People with TS may have genetic risks for other neurobehavioral disorders such as depression or substance abuse. Genetic counseling of individuals with TS should include a full review of all potentially hereditary conditions in the family.

Treatments

Because symptoms do not impair most patients and development usually proceeds normally, the majority of people with TS require no medication. However, medications are available to help when symptoms interfere with functioning. Unfortunately, there is no one medication that is helpful to all persons with TS, nor does any medication completely eliminate symptoms; in addition, all medications have side effects. Instead, the available TS medications are only able to help reduce specific symptoms.

Some patients who require medication to reduce the frequency and intensity of the tic symptoms may be treated with neuroleptic drugs such as haloperidol and pimozide. These medications are usually given in very small doses that are increased slowly until the best possible balance between symptoms and side effects is achieved.

Neurological side effects such as tremor, dystonic reactions (twisting movements or postures), Parkinsonian-like symptoms, and other dyskinetic (involuntary) movements are less common and are readily managed with dose reduction. Discontinuing neuroleptics after long-term use must be done slowly to avoid rebound increases in tics and withdrawal dyskinesias.

Recently scientists have discovered that long-term use of neuroleptic drugs may cause an involuntary movement disorder called tardive dyskinesia. However, this condition usually disappears when medication is discontinued. These side effects can be reduced by drugs commonly used to treat Parkinson's disease. Other side effects such as fatigue, depression, anxiety, weight gain and difficulties in thinking clearly may be more troublesome.

Clonidine and guanfacine, both antihypertensive drugs, are also used in the treatment of tics. The most common side effect from these medications that precludes their use is sedation. Fatigue, dry mouth, irritability, dizziness, headache, and insomnia are common side effects associated with clonidine use. Fluphenazine and clonazepam may also be prescribed to help control tic symptoms.

Effective medications are also available to treat some of the associated behavioral disorders. Stimulants such as methyphenidate and dextroamphetamine, usually prescribed for attention deficit-hyperactivity disorders, have also been reported to be effective without causing tics to become more severe. For obsessive-compulsive behaviors that significantly disrupt daily functioning, fluoxetine, clomipramine, sertraline or paroxetine may be prescribed.

Other types of therapy may also be helpful. Although psychological problems do not cause TS, psychotherapy may help the person better cope with the disorder and deal with the secondary social and emotional problems that sometimes occur. Psychotherapy does not help suppress the patient's tics. More recently, specific behavioral treatments that include awareness training and competing response training, such as voluntarily moving in response to a premonitory urge, have shown effectiveness in small controlled trials. Larger and more definitive NIH-funded studies are underway.

Relaxation techniques and biofeedback may be useful in alleviating stress that can lead to an increase in tic symptoms.

What is the prognosis?

Although there is no cure for TS, the condition in many individuals improves as they mature. Individuals with TS can expect to live a normal life span. Although the disorder is generally lifelong and chronic, it is not a degenerative condition. TS does not impair intelligence. Tics tend to decrease with age, enabling some patients to discontinue using medication. In a few cases, complete remission occurs after adolescence. Although tic symptoms tend to decrease with age, it is possible that neurobehavioral disorders such as depression, panic attacks, mood swings and antisocial behaviors can persist and cause impairment in adult life.

What is the best educational setting for children with TS?

Although students with TS often function well in the regular classroom, it is estimated that many may have some kind of learning disability. When attention deficit-hyperactivity disorder, obsessive-compulsive disorder, and frequent tics greatly interfere with academic performance or social adjustment, students should be placed in an educational setting that meets their individual needs. These students may require tutoring, smaller or special classes and, in some cases, special schools.

All students with TS need a tolerant and compassionate setting that both encourages them to work to their full potential and is flexible enough to accommodate their special needs. This setting may include a private study area, exams outside the regular classroom, or even oral exams when the child's symptoms interfere with his or her ability to write. Untimed testing reduces stress for students with TS.

Sources

Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition

Revised National Institute of Neurological Disorders and Stroke

National Institutes of Health National Institutes of Health - National Library of Medicine